Combination antennas but also traditional antenna mounts are mounted in a round hole having a diameter of approx. 14-20 mm. The mount has a corresponding bolt that fits the dimension of the hole. Occasionally, also adapter rings are found to adapt the bolt to the dimension of the hole. The antenna is attached by a toothed plate connector and a nut being mounted from the underside and tightened.
A disadvantage of this mounting is that the antenna needs to be aligned/orientated since the hole is round. In addition, the fitting is carried out from two directions. The antenna is difficult to hold in place by one person during the fitting of the nut. Upon fitting in great vehicles, the installation engineer needs to work with the hands high stretched over the head, which from working-environment point of view is not allowed. In serial production today, antennas of this type are mounted by two persons, which is not cost-effective.
Another known antenna mount is designed in such a way that it is possible to mount from the outside by it being angled/threaded down into a round hole having a diameter of approx. 20 mm. Then, the gasket and nut are mounted to tighten the mount. Finally, a flexible section and the antenna are mounted. The mounting is normally used only for rod antennas, since the proper mount has to be small both on the inside and the outside.
A disadvantage of this mounting is that the antenna needs to be aligned/orientated since the hole is round, unless the antenna is symmetrical. In addition, the antenna is difficult to hold in place, at the same time as the gasket and nut are threaded in place. There is a risk that the orientation is changed when the nut is tightened. An additional disadvantage is that the antenna mount comes with a plurality of loose parts in a bag. In serial production, the parts are picked out of the bag and are laid in a trough that then is moved out to the vehicle, which is not cost-effective. Furthermore, a part may easily be lost and an entire antenna needs to be discarded. During fitting, several parts may be lost and disappear alternatively get into places in the vehicle or in the mechanics of conveyor belts, in line production, and create problems.
An alternative mounting of this antenna mount is that the mount is mounted from the underside and the nut from the upperside.
An additional disadvantage of this mounting is that the fitting is carried out from two directions. This means that in serial production, antennas of this type are today mounted by two persons, which is not cost-effective.
Another known way is to mount the mount/antenna on the vehicle using adhesive/tape. This type of mounting is found in fitting of so-called shark fins on vehicles.
A disadvantage of this way of mounting is that the antenna needs to be aligned/orientated. In serial production, a robot is required that presses the antenna in place in a controlled way using the correct pressure and position. In addition, it is extremely important that the surface is cleaned before the tape is mounted. An additional disadvantage is that if the antenna is damaged, it is difficult to dismount the unit. The antenna mount cannot be equipped with long rods. The torque becomes great and there is a risk that the mount gets loose over time. An additional disadvantage is that it cannot be mounted in all temperatures.
The patent document US-2007/0075904 A1 discloses a method for the attachment of an antenna to a surface. The surface is a pressed surface where a self-tapping screw is mounted through the sheet-metal plate, alternatively a press nut or clip on is used.
The disadvantage of this is that the installation requires that the fitting surface is machined in a special way in the production, on one hand because of the pressing but also further fitting of press nut, which requires more time and consequently higher costs. An additional disadvantage is that all force is located around one position, which makes that rods for lower frequencies presumably cannot be mounted. The machining of the surface requires great presses and cannot be carried out afterwards.
The patent document EP-1, 928, 054 A1 discloses an antenna that is fixed by a snap until it is possible to fix the antenna by a screw from the underside.
The solution is inappropriate in respect of a mounting sequence with a screw from the underside. In addition, it is not possible to dismount the antenna without special tools or destroying the snap. Furthermore, the solution is not suitable in antenna configurations that require longer rods and accordingly greater forces upon the fastening.
The patent document US-2003/0089834 A1 discloses a method of temporary attaching an antenna so that it does not “falls out of” the hole upon fitting with the nut on the inside.
The method is not applicable for permanent fastening but requires an additional attachment according to traditional methods, so called “threaded bolt”.